For my Choice Project, I opted to use Voice Thread. Voice thread can act as an outlet for students who struggle to write in essay form, painting their perception visually and allowing them a vocal explanation. For teachers, Voice Thread is a great way to present information to their students in a way different than the traditional lecture.
Taken From: http://www.scribd.com/fullscreen/5357929?access_key=key-2fqzuh6lvsw04qlc6dh3
Below is a more concise tutorial that quickly explains how to use Voice Thread.